title: Efficacy of platelet-rich plasma for chronic tennis elbow: a double-blind, prospective, multicenter, randomized controlled trial of 230 patients.
abstract: BACKGROUND
  Elbow tenderness and pain with resisted wrist extension are common manifestations of lateral epicondylar tendinopathy, also known as tennis elbow. Previous studies have suggested platelet-rich plasma (PRP) to be a safe and effective therapy for tennis elbow.
  
  
  OBJECTIVE
  To evaluate the clinical value of tendon needling with PRP in patients with chronic tennis elbow compared with an active control group.
  
  
  METHODS
  Randomized controlled trial; Level of evidence, 2.
  
  
  METHODS
  A total of 230 patients with chronic lateral epicondylar tendinopathy were treated at 12 centers over 5 years. All patients had at least 3 months of symptoms and had failed conventional therapy. There were no differences in patients randomized to receive PRP (n = 116) or active controls (n = 114). The PRP was prepared from venous whole blood at the point of care and contained both concentrated platelets and leukocytes. After receiving a local anesthetic, all patients had their extensor tendons needled with or without PRP. Patients and investigators remained blinded to the treatment group throughout the study. A successful outcome was defined as 25% or greater improvement on the visual analog scale for pain.
  
  
  RESULTS
  Patient outcomes were followed for up to 24 weeks. At 12 weeks (n = 192), the PRP-treated patients reported an improvement of 55.1% in their pain scores compared with 47.4% in the active control group (P = .163). At 24 weeks (n = 119), the PRP-treated patients reported an improvement of 71.5% in their pain scores compared with 56.1% in the control group (P = .019). The percentage of patients reporting significant elbow tenderness at 12 weeks was 37.4% in the PRP group versus 48.4% in the control group (P = .143). Success rates for patients at 12 weeks were 75.2% in the PRP group versus 65.9% in the control group (P = .104). At 24 weeks, 29.1% of the PRP-treated patients reported significant elbow tenderness versus 54.0% in the control group (P = .009). Success rates for patients with 24 weeks of follow-up were 83.9% in the PRP group compared with 68.3% in the control group (P = .037). No significant complications occurred in either group.
  
  
  CONCLUSIONS
  No significant differences were found at 12 weeks in this study. At 24 weeks, however, clinically meaningful improvements were found in patients treated with leukocyte-enriched PRP compared with an active control group.
authors.affiliation: Allan K. Mishra, Department of Orthopedic Surgery, Menlo Medical Clinic, Stanford University Medical Center, 1300 Crane Street, Menlo Park, CA 94025. am@totaltendon.com.
authors.forename: Allan K
authors.initials: AK
authors.lastname: Mishra
authors.forename: Nebojsa V
authors.initials: NV
authors.lastname: Skrepnik
authors.forename: Scott G
authors.initials: SG
authors.lastname: Edwards
authors.forename: Grant L
authors.initials: GL
authors.lastname: Jones
authors.forename: Steven
authors.initials: S
authors.lastname: Sampson
authors.forename: Doug A
authors.initials: DA
authors.lastname: Vermillion
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Ramsey
authors.forename: David C
authors.initials: DC
authors.lastname: Karli
authors.forename: Arthur C
authors.initials: AC
authors.lastname: Rettig
mesh_terms: D000328:Adult; D002908:Chronic Disease; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D053657:Platelet-Rich Plasma; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D013716:Tennis Elbow / Q000628:therapy*; D016896:Treatment Outcome
keywords: lateral epicondylitis; platelet; platelet-rich plasma (PRP); tendinopathy; tennis elbow